Protein crystallography is an extremely powerful tool to determine the three-dimensional, high resolution structures of proteins. However, protein crystallography is technically demanding, and requires expensive instrumentation and highly skilled and experienced personnel. The purpose of Core B is to provide this expertise and make it possible for all members of the Program Project to apply these techniques in their program related research. Personnel associated with Core B have considerable experience in all facets of protein crystallography for the last 25 years. He was the inventor of the "Multiwire Area Detectors" which revolutionized the data collection method for protein crystallography. He has also run an NIH Resource Center for protein crystallography for 10 years. Dr. Madhusudan, the scientific director, has used protein crystallography for many years to successfully solve many protein structures. His expertise is specifically in the area of protein kinase. Mr. Chris Nielsen is an experienced programmer who has worked on data collection and analysis for almost 20 years. We intend to operate the facility as a state-of-the-art Core to serve laboratory program members. Three crystallographic projects are proposed. (1) High resolution structures of the dual specific A-Kinase Anchoring Proteins, the D-AKAP's, that interaction with both RI and RII subunits of PKA (Project 1: Taylor) will be solved both in the absence and presence of the dimerization/docking domain or the full length RI and RII subunits. (2) High resolution structures of the PKC kinase domain, with its's carboxyl terminal docking domain in the dephosphorylated or phosphorylated form (Project 3:Newton (3). The structure of the newly discovered AKAP in gravin will be solved alone and as a complex with the dimerization/docking domain of RIIa and RIIb. (Project 2:Scott and Project 4:Jennings).